attachment from network other computer,
You are probably running into this.
https://activedirectoryfaq.com/2015/04/mapped-drives-are-not-available-in-windows-explorer/
Due to security reasons, the two contexts do not share all available information. Besides other things, drive mappings are not shared between “Admin” and “User” contexts.
Use a UNC path instead of a drive letter or follow the instructions in the section: Solution: How to make mapped drives visible